code.delx.au - gnu-emacs/blob - lib-src/emacsclient.c

   1 /* Client process that communicates with GNU Emacs acting as server.
   2    Copyright (C) 1986, 1987, 1994, 1999, 2000, 2001, 2003, 2004
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs; see the file COPYING.  If not, write to
  19 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20 Boston, MA 02110-1301, USA.  */
  21
  22
  23 #define NO_SHORTNAMES
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include <config.h>
  27 #endif
  28
  29 #undef signal
  30
  31 #include <ctype.h>
  32 #include <stdio.h>
  33 #include <getopt.h>
  34 #ifdef HAVE_UNISTD_H
  35 #include <unistd.h>
  36 #endif
  37
  38 #ifdef VMS
  39 # include "vms-pwd.h"
  40 #else
  41 # include <pwd.h>
  42 #endif /* not VMS */
  43
  44 #include <signal.h>
  45 #include <errno.h>
  46
  47 \f
  48 char *getenv (), *getwd ();
  49 char *(getcwd) ();
  50
  51 #ifndef VERSION
  52 #define VERSION "unspecified"
  53 #endif
  54 \f
  55 /* Name used to invoke this program.  */
  56 char *progname;
  57
  58 /* The first argument to main. */
  59 int main_argc;
  60
  61 /* The second argument to main. */
  62 char **main_argv;
  63
  64 /* Nonzero means don't wait for a response from Emacs.  --no-wait.  */
  65 int nowait = 0;
  66
  67 /* Nonzero means args are expressions to be evaluated.  --eval.  */
  68 int eval = 0;
  69
  70 /* Nonzero means open a new graphical frame. */
  71 int window_system = 0;
  72
  73 /* The display on which Emacs should work.  --display.  */
  74 char *display = NULL;
  75
  76 /* Nonzero means open a new Emacs frame on the current terminal. */
  77 int tty = 0;
  78
  79 /* If non-NULL, the name of an editor to fallback to if the server
  80    is not running.  --alternate-editor.   */
  81 const char * alternate_editor = NULL;
  82
  83 /* If non-NULL, the filename of the UNIX socket.  */
  84 char *socket_name = NULL;
  85
  86 void print_help_and_exit ();
  87
  88 struct option longopts[] =
  89 {
  90   { "no-wait",  no_argument,       NULL, 'n' },
  91   { "eval",     no_argument,       NULL, 'e' },
  92   { "help",     no_argument,       NULL, 'H' },
  93   { "version",  no_argument,       NULL, 'V' },
  94   { "tty",      no_argument,       NULL, 't' },
  95   { "current-frame", no_argument,  NULL, 'c' },
  96   { "alternate-editor", required_argument, NULL, 'a' },
  97   { "socket-name",      required_argument, NULL, 's' },
  98   { "display",  required_argument, NULL, 'd' },
  99   { 0, 0, 0, 0 }
 100 };
 101
 102 /* Decode the options from argv and argc.
 103    The global variable `optind' will say how many arguments we used up.  */
 104
 105 void
 106 decode_options (argc, argv)
 107      int argc;
 108      char **argv;
 109 {
 110   alternate_editor = getenv ("ALTERNATE_EDITOR");
 111   display = getenv ("DISPLAY");
 112   if (display && strlen (display) == 0)
 113     display = NULL;
 114
 115   if (display)
 116     window_system = 1;
 117   else
 118     tty = 1;
 119
 120   while (1)
 121     {
 122       int opt = getopt_long (argc, argv,
 123                              "VHnea:s:d:tc", longopts, 0);
 124
 125       if (opt == EOF)
 126         break;
 127
 128       switch (opt)
 129         {
 130         case 0:
 131           /* If getopt returns 0, then it has already processed a
 132              long-named option.  We should do nothing.  */
 133           break;
 134
 135         case 'a':
 136           alternate_editor = optarg;
 137           break;
 138
 139         case 's':
 140           socket_name = optarg;
 141           break;
 142
 143         case 'd':
 144           display = optarg;
 145           break;
 146
 147         case 'n':
 148           nowait = 1;
 149           break;
 150
 151         case 'e':
 152           eval = 1;
 153           break;
 154
 155         case 'V':
 156           printf ("emacsclient %s\n", VERSION);
 157           exit (EXIT_SUCCESS);
 158           break;
 159
 160         case 't':
 161           tty = 1;
 162           window_system = 0;
 163           break;
 164
 165         case 'c':
 166           window_system = 0;
 167           tty = 0;
 168           break;
 169
 170         case 'H':
 171           print_help_and_exit ();
 172           break;
 173
 174         default:
 175           fprintf (stderr, "Try `%s --help' for more information\n", progname);
 176           exit (EXIT_FAILURE);
 177           break;
 178         }
 179     }
 180
 181   if (tty) {
 182     nowait = 0;
 183     display = 0;
 184   }
 185 }
 186
 187 void
 188 print_help_and_exit ()
 189 {
 190   printf (
 191           "Usage: %s [OPTIONS] FILE...\n\
 192 Tell the Emacs server to visit the specified files.\n\
 193 Every FILE can be either just a FILENAME or [+LINE[:COLUMN]] FILENAME.\n\
 194 \n\
 195 The following OPTIONS are accepted:\n\
 196 -V, --version           Just print a version info and return\n\
 197 -H, --help              Print this usage information message\n\
 198 -t, --tty               Open a new Emacs frame on the current terminal\n\
 199 -c, --current-frame     Do not create a new frame; use the current Emacs frame\n\
 200 -n, --no-wait           Don't wait for the server to return\n\
 201 -e, --eval              Evaluate the FILE arguments as ELisp expressions\n\
 202 -d, --display=DISPLAY   Visit the file in the given display\n\
 203 -s, --socket-name=FILENAME\n\
 204                         Set the filename of the UNIX socket for communication\n\
 205 -a, --alternate-editor=EDITOR\n\
 206                         Editor to fallback to if the server is not running\n\
 207 \n\
 208 Report bugs to bug-gnu-emacs@gnu.org.\n", progname);
 209   exit (EXIT_SUCCESS);
 210 }
 211
 212 /* Like malloc but get fatal error if memory is exhausted.  */
 213
 214 long *
 215 xmalloc (size)
 216      unsigned int size;
 217 {
 218   long *result = (long *) malloc (size);
 219   if (result == NULL)
 220     {
 221       perror ("malloc");
 222       exit (EXIT_FAILURE);
 223     }
 224   return result;
 225 }
 226
 227 /* Like strdup but get a fatal error if memory is exhausted. */
 228
 229 char *
 230 xstrdup (const char *s)
 231 {
 232   char *result = strdup (s);
 233   if (result == NULL)
 234     {
 235       perror ("strdup");
 236       exit (EXIT_FAILURE);
 237     }
 238   return result;
 239 }
 240
 241 /* In STR, insert a & before each &, each space, each newline, and
 242    any initial -.  Change spaces to underscores, too, so that the
 243    return value never contains a space.
 244
 245    Does not change the string.  Outputs the result to STREAM.  */
 246
 247 void
 248 quote_argument (str, stream)
 249      char *str;
 250      FILE *stream;
 251 {
 252   char *copy = (char *) xmalloc (strlen (str) * 2 + 1);
 253   char *p, *q;
 254
 255   p = str;
 256   q = copy;
 257   while (*p)
 258     {
 259       if (*p == ' ')
 260         {
 261           *q++ = '&';
 262           *q++ = '_';
 263           p++;
 264         }
 265       else if (*p == '\n')
 266         {
 267           *q++ = '&';
 268           *q++ = 'n';
 269           p++;
 270         }
 271       else
 272         {
 273           if (*p == '&' || (*p == '-' && p == str))
 274             *q++ = '&';
 275           *q++ = *p++;
 276         }
 277     }
 278   *q++ = 0;
 279
 280   fprintf (stream, "%s", copy);
 281
 282   free (copy);
 283 }
 284
 285
 286 /* The inverse of quote_argument.  Removes quoting in string STR by
 287    modifying the string in place.   Returns STR. */
 288
 289 char *
 290 unquote_argument (str)
 291      char *str;
 292 {
 293   char *p, *q;
 294
 295   if (! str)
 296     return str;
 297
 298   p = str;
 299   q = str;
 300   while (*p)
 301     {
 302       if (*p == '&')
 303         {
 304           p++;
 305           if (*p == '&')
 306             *p = '&';
 307           else if (*p == '_')
 308             *p = ' ';
 309           else if (*p == 'n')
 310             *p = '\n';
 311           else if (*p == '-')
 312             *p = '-';
 313         }
 314       *q++ = *p++;
 315     }
 316   *q = 0;
 317   return str;
 318 }
 319
 320 \f
 321 /*
 322   Try to run a different command, or --if no alternate editor is
 323   defined-- exit with an errorcode.
 324 */
 325 void
 326 fail (void)
 327 {
 328   if (alternate_editor)
 329     {
 330       int i = optind - 1;
 331       execvp (alternate_editor, main_argv + i);
 332       return;
 333     }
 334   else
 335     {
 336       exit (EXIT_FAILURE);
 337     }
 338 }
 339
 340 /* The process id of Emacs. */
 341 int emacs_pid;
 342
 343 /* File handles for communicating with Emacs. */
 344 FILE *out, *in;
 345
 346 /* A signal handler that passes the signal to the Emacs process.
 347    Useful for SIGWINCH.  */
 348
 349 SIGTYPE
 350 pass_signal_to_emacs (int signalnum)
 351 {
 352   int old_errno = errno;
 353
 354   if (emacs_pid)
 355     kill (emacs_pid, signalnum);
 356
 357   signal (signalnum, pass_signal_to_emacs);
 358   errno = old_errno;
 359 }
 360
 361 /* Signal handler for SIGCONT; notify the Emacs process that it can
 362    now resume our tty frame.  */
 363
 364 SIGTYPE
 365 handle_sigcont (int signalnum)
 366 {
 367   int old_errno = errno;
 368
 369   if (tcgetpgrp (1) == getpgrp ())
 370     {
 371       /* We are in the foreground. */
 372       fprintf (out, "-resume \n");
 373       fflush (out);
 374       fsync (fileno (out));
 375     }
 376   else
 377     {
 378       /* We are in the background; cancel the continue. */
 379       kill (getpid (), SIGSTOP);
 380     }
 381   errno = old_errno;
 382 }
 383
 384 /* Signal handler for SIGTSTP; notify the Emacs process that we are
 385    going to sleep.  Normally the suspend is initiated by Emacs via
 386    server-handle-suspend-tty, but if the server gets out of sync with
 387    reality, we may get a SIGTSTP on C-z.  Handling this signal and
 388    notifying Emacs about it should get things under control again. */
 389
 390 SIGTYPE
 391 handle_sigtstp (int signalnum)
 392 {
 393   int old_errno = errno;
 394   sigset_t set;
 395
 396   if (out)
 397     {
 398       fprintf (out, "-suspend \n");
 399       fflush (out);
 400       fsync (fileno (out));
 401     }
 402
 403   /* Unblock this signal and call the default handler by temprarily
 404      changing the handler and resignalling. */
 405   sigprocmask (SIG_BLOCK, NULL, &set);
 406   sigdelset (&set, signalnum);
 407   signal (signalnum, SIG_DFL);
 408   kill (getpid (), signalnum);
 409   sigprocmask (SIG_SETMASK, &set, NULL); /* Let's the above signal through. */
 410   signal (signalnum, handle_sigtstp);
 411
 412   errno = old_errno;
 413 }
 414
 415 /* Set up signal handlers before opening a frame on the current tty.  */
 416
 417 void
 418 init_signals (void)
 419 {
 420   /* Set up signal handlers. */
 421   signal (SIGWINCH, pass_signal_to_emacs);
 422
 423   /* Don't pass SIGINT and SIGQUIT to Emacs, because it has no way of
 424      deciding which terminal the signal came from.  C-g is now a
 425      normal input event on secondary terminals.  */
 426 #if 0
 427   signal (SIGINT, pass_signal_to_emacs);
 428   signal (SIGQUIT, pass_signal_to_emacs);
 429 #endif
 430
 431   signal (SIGCONT, handle_sigcont);
 432   signal (SIGTSTP, handle_sigtstp);
 433   signal (SIGTTOU, handle_sigtstp);
 434 }
 435
 436 \f
 437 #if !defined (HAVE_SOCKETS) || defined (NO_SOCKETS_IN_FILE_SYSTEM)
 438
 439 int
 440 main (argc, argv)
 441      int argc;
 442      char **argv;
 443 {
 444   fprintf (stderr, "%s: Sorry, the Emacs server is supported only\n",
 445            argv[0]);
 446   fprintf (stderr, "on systems with Berkeley sockets.\n");
 447
 448   fail ();
 449 }
 450
 451 #else /* HAVE_SOCKETS */
 452
 453 #include <sys/types.h>
 454 #include <sys/socket.h>
 455 #include <sys/un.h>
 456 #include <sys/stat.h>
 457 #include <errno.h>
 458
 459 extern char *strerror ();
 460 extern int errno;
 461
 462 /* Three possibilities:
 463    2 - can't be `stat'ed                (sets errno)
 464    1 - isn't owned by us
 465    0 - success: none of the above */
 466
 467 static int
 468 socket_status (socket_name)
 469      char *socket_name;
 470 {
 471   struct stat statbfr;
 472
 473   if (stat (socket_name, &statbfr) == -1)
 474     return 2;
 475
 476   if (statbfr.st_uid != geteuid ())
 477     return 1;
 478
 479   return 0;
 480 }
 481
 482 /* Returns 1 if PREFIX is a prefix of STRING. */
 483 static int
 484 strprefix (char *prefix, char *string)
 485 {
 486   int i;
 487   if (! prefix)
 488     return 1;
 489
 490   if (!string)
 491     return 0;
 492
 493   for (i = 0; prefix[i]; i++)
 494     if (!string[i] || string[i] != prefix[i])
 495       return 0;
 496   return 1;
 497 }
 498
 499 int
 500 main (argc, argv)
 501      int argc;
 502      char **argv;
 503 {
 504   int s, i, needlf = 0;
 505   struct sockaddr_un server;
 506   char *cwd, *str;
 507   char string[BUFSIZ];
 508
 509   main_argc = argc;
 510   main_argv = argv;
 511   progname = argv[0];
 512
 513   /* Process options.  */
 514   decode_options (argc, argv);
 515
 516   if ((argc - optind < 1) && !eval && !tty && !window_system)
 517     {
 518       fprintf (stderr, "%s: file name or argument required\n", progname);
 519       fprintf (stderr, "Try `%s --help' for more information\n", progname);
 520       exit (EXIT_FAILURE);
 521     }
 522
 523   /*
 524    * Open up an AF_UNIX socket in this person's home directory
 525    */
 526
 527   if ((s = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
 528     {
 529       fprintf (stderr, "%s: ", argv[0]);
 530       perror ("socket");
 531       fail ();
 532     }
 533
 534   server.sun_family = AF_UNIX;
 535
 536   {
 537     int sock_status = 0;
 538     int default_sock = !socket_name;
 539     int saved_errno = 0;
 540
 541      char *server_name = "server";
 542
 543      if (socket_name && !index (socket_name, '/') && !index (socket_name, '\\'))
 544        { /* socket_name is a file name component.  */
 545         server_name = socket_name;
 546         socket_name = NULL;
 547         default_sock = 1;       /* Try both UIDs.  */
 548        }
 549
 550      if (default_sock)
 551       {
 552         socket_name = alloca (100 + strlen (server_name));
 553         sprintf (socket_name, "/tmp/emacs%d/%s",
 554                  (int) geteuid (), server_name);
 555       }
 556
 557     if (strlen (socket_name) < sizeof (server.sun_path))
 558       strcpy (server.sun_path, socket_name);
 559     else
 560       {
 561         fprintf (stderr, "%s: socket-name %s too long",
 562                  argv[0], socket_name);
 563         fail ();
 564       }
 565
 566     /* See if the socket exists, and if it's owned by us. */
 567     sock_status = socket_status (server.sun_path);
 568     saved_errno = errno;
 569     if (sock_status && default_sock)
 570       {
 571         /* Failing that, see if LOGNAME or USER exist and differ from
 572            our euid.  If so, look for a socket based on the UID
 573            associated with the name.  This is reminiscent of the logic
 574            that init_editfns uses to set the global Vuser_full_name.  */
 575
 576         char *user_name = (char *) getenv ("LOGNAME");
 577
 578         if (!user_name)
 579           user_name = (char *) getenv ("USER");
 580
 581         if (user_name)
 582           {
 583             struct passwd *pw = getpwnam (user_name);
 584
 585             if (pw && (pw->pw_uid != geteuid ()))
 586               {
 587                 /* We're running under su, apparently. */
 588                 socket_name = alloca (100 + strlen (server_name));
 589                 sprintf (socket_name, "/tmp/emacs%d/%s",
 590                          (int) pw->pw_uid, server_name);
 591
 592                 if (strlen (socket_name) < sizeof (server.sun_path))
 593                   strcpy (server.sun_path, socket_name);
 594                 else
 595                   {
 596                     fprintf (stderr, "%s: socket-name %s too long",
 597                              argv[0], socket_name);
 598                     exit (EXIT_FAILURE);
 599                   }
 600
 601                 sock_status = socket_status (server.sun_path);
 602                 saved_errno = errno;
 603               }
 604             else
 605               errno = saved_errno;
 606           }
 607       }
 608
 609      switch (sock_status)
 610        {
 611        case 1:
 612          /* There's a socket, but it isn't owned by us.  This is OK if
 613             we are root. */
 614          if (0 != geteuid ())
 615            {
 616              fprintf (stderr, "%s: Invalid socket owner\n", argv[0]);
 617              fail ();
 618            }
 619          break;
 620
 621        case 2:
 622          /* `stat' failed */
 623          if (saved_errno == ENOENT)
 624            fprintf (stderr,
 625                     "%s: can't find socket; have you started the server?\n\
 626 To start the server in Emacs, type \"M-x server-start\".\n",
 627                     argv[0]);
 628          else
 629            fprintf (stderr, "%s: can't stat %s: %s\n",
 630                     argv[0], server.sun_path, strerror (saved_errno));
 631          fail ();
 632          break;
 633        }
 634   }
 635
 636   if (connect (s, (struct sockaddr *) &server, strlen (server.sun_path) + 2)
 637       < 0)
 638     {
 639       fprintf (stderr, "%s: ", argv[0]);
 640       perror ("connect");
 641       fail ();
 642     }
 643
 644   /* We use the stream OUT to send our commands to the server.  */
 645   if ((out = fdopen (s, "r+")) == NULL)
 646     {
 647       fprintf (stderr, "%s: ", argv[0]);
 648       perror ("fdopen");
 649       fail ();
 650     }
 651
 652   /* We use the stream IN to read the responses.
 653      We used to use just one stream for both output and input
 654      on the socket, but reversing direction works nonportably:
 655      on some systems, the output appears as the first input;
 656      on other systems it does not.  */
 657   if ((in = fdopen (s, "r+")) == NULL)
 658     {
 659       fprintf (stderr, "%s: ", argv[0]);
 660       perror ("fdopen");
 661       fail ();
 662     }
 663
 664 #ifdef HAVE_GETCWD
 665   cwd = getcwd (string, sizeof string);
 666 #else
 667   cwd = getwd (string);
 668 #endif
 669   if (cwd == 0)
 670     {
 671       /* getwd puts message in STRING if it fails.  */
 672
 673 #ifdef HAVE_GETCWD
 674       fprintf (stderr, "%s: %s (%s)\n", argv[0],
 675                "cannot get current working directory", strerror (errno));
 676 #else
 677       fprintf (stderr, "%s: %s (%s)\n", argv[0], string, strerror (errno));
 678 #endif
 679       fail ();
 680     }
 681
 682   /* First of all, send our version number for verification. */
 683   fprintf (out, "-version %s ", VERSION);
 684
 685   /* Send over our environment. */
 686   {
 687     extern char **environ;
 688     int i;
 689     for (i = 0; environ[i]; i++)
 690       {
 691         char *name = xstrdup (environ[i]);
 692         char *value = strchr (name, '=');
 693         if (value && strlen (value) > 1)
 694           {
 695             *value++ = 0;
 696             fprintf (out, "-env ");
 697             quote_argument (name, out);
 698             fprintf (out, " ");
 699             quote_argument (value, out);
 700             fprintf (out, " ");
 701             fflush (out);
 702           }
 703         free (name);
 704       }
 705   }
 706
 707  retry:
 708   if (nowait)
 709     fprintf (out, "-nowait ");
 710
 711   if (display)
 712     {
 713       fprintf (out, "-display ");
 714       quote_argument (display, out);
 715       fprintf (out, " ");
 716     }
 717
 718   if (tty)
 719     {
 720       char *tty_name = ttyname (fileno (stdin));
 721       char *type = getenv ("TERM");
 722
 723       if (! tty_name)
 724         {
 725           fprintf (stderr, "%s: could not get terminal name\n", progname);
 726           fail ();
 727         }
 728
 729       if (! type)
 730         {
 731           fprintf (stderr, "%s: please set the TERM variable to your terminal type\n",
 732                    progname);
 733           fail ();
 734         }
 735
 736       if (! strcmp (type, "eterm"))
 737         {
 738           /* This causes nasty, MULTI_KBOARD-related input lockouts. */
 739           fprintf (stderr, "%s: opening a frame in an Emacs term buffer"
 740                    " is not supported\n", progname);
 741           fail ();
 742         }
 743
 744       init_signals ();
 745
 746       fprintf (out, "-tty ");
 747       quote_argument (tty_name, out);
 748       fprintf (out, " ");
 749       quote_argument (type, out);
 750       fprintf (out, " ");
 751     }
 752
 753   if (window_system)
 754     fprintf (out, "-window-system ");
 755
 756   if ((argc - optind > 0))
 757     {
 758       for (i = optind; i < argc; i++)
 759         {
 760           int relative = 0;
 761
 762           if (eval)
 763             {
 764               /* Don't prepend any cwd or anything like that.  */
 765               fprintf (out, "-eval ");
 766               quote_argument (argv[i], out);
 767               fprintf (out, " ");
 768               continue;
 769             }
 770
 771           if (*argv[i] == '+')
 772             {
 773               char *p = argv[i] + 1;
 774               while (isdigit ((unsigned char) *p) || *p == ':') p++;
 775               if (*p == 0)
 776                 {
 777                   fprintf (out, "-position ");
 778                   quote_argument (argv[i], out);
 779                   fprintf (out, " ");
 780                   continue;
 781                 }
 782               else
 783                 relative = 1;
 784             }
 785           else if (*argv[i] != '/')
 786             relative = 1;
 787
 788           fprintf (out, "-file ");
 789           if (relative)
 790             {
 791               quote_argument (cwd, out);
 792               fprintf (out, "/");
 793             }
 794           quote_argument (argv[i], out);
 795           fprintf (out, " ");
 796         }
 797     }
 798   else
 799     {
 800       if (!tty && !window_system)
 801         {
 802           while ((str = fgets (string, BUFSIZ, stdin)))
 803             {
 804               if (eval)
 805                 fprintf (out, "-eval ");
 806               else
 807                 fprintf (out, "-file ");
 808               quote_argument (str, out);
 809             }
 810           fprintf (out, " ");
 811         }
 812     }
 813
 814   fprintf (out, "\n");
 815   fflush (out);
 816   fsync (fileno (out));
 817
 818   /* Wait for an answer. */
 819   if (!eval && !tty && !nowait)
 820     {
 821       printf ("Waiting for Emacs...");
 822       needlf = 2;
 823     }
 824   fflush (stdout);
 825   fsync (1);
 826
 827   /* Now, wait for an answer and print any messages.  */
 828   while ((str = fgets (string, BUFSIZ, in)))
 829     {
 830       char *p = str + strlen (str) - 1;
 831       while (p > str && *p == '\n')
 832         *p-- = 0;
 833
 834       if (strprefix ("-good-version ", str))
 835         {
 836           /* -good-version: The versions match. */
 837         }
 838       else if (strprefix ("-emacs-pid ", str))
 839         {
 840           /* -emacs-pid PID: The process id of the Emacs process. */
 841           emacs_pid = strtol (string + strlen ("-emacs-pid"), NULL, 10);
 842         }
 843       else if (strprefix ("-window-system-unsupported ", str))
 844         {
 845           /* -window-system-unsupported: Emacs was compiled without X
 846               support.  Try again on the terminal. */
 847           window_system = 0;
 848           nowait = 0;
 849           tty = 1;
 850           goto retry;
 851         }
 852       else if (strprefix ("-print ", str))
 853         {
 854           /* -print STRING: Print STRING on the terminal. */
 855           str = unquote_argument (str + strlen ("-print "));
 856           if (needlf)
 857             printf ("\n");
 858           printf ("%s", str);
 859           needlf = str[0] == '\0' ? needlf : str[strlen (str) - 1] != '\n';
 860         }
 861       else if (strprefix ("-error ", str))
 862         {
 863           /* -error DESCRIPTION: Signal an error on the terminal. */
 864           str = unquote_argument (str + strlen ("-error "));
 865           if (needlf)
 866             printf ("\n");
 867           printf ("*ERROR*: %s", str);
 868           needlf = str[0] == '\0' ? needlf : str[strlen (str) - 1] != '\n';
 869         }
 870       else if (strprefix ("-suspend ", str))
 871         {
 872           /* -suspend: Suspend this terminal, i.e., stop the process. */
 873           if (needlf)
 874             printf ("\n");
 875           needlf = 0;
 876           kill (0, SIGSTOP);
 877         }
 878       else
 879         {
 880           /* Unknown command. */
 881           if (needlf)
 882             printf ("\n");
 883           printf ("*ERROR*: Unknown message: %s", str);
 884           needlf = str[0] == '\0' ? needlf : str[strlen (str) - 1] != '\n';
 885         }
 886     }
 887
 888   if (needlf)
 889     printf ("\n");
 890   fflush (stdout);
 891   fsync (1);
 892
 893   return EXIT_SUCCESS;
 894 }
 895
 896 #endif /* HAVE_SOCKETS */
 897 \f
 898 #ifndef HAVE_STRERROR
 899 char *
 900 strerror (errnum)
 901      int errnum;
 902 {
 903   extern char *sys_errlist[];
 904   extern int sys_nerr;
 905
 906   if (errnum >= 0 && errnum < sys_nerr)
 907     return sys_errlist[errnum];
 908   return (char *) "Unknown error";
 909 }
 910
 911 #endif /* ! HAVE_STRERROR */
 912
 913 /* arch-tag: f39bb9c4-73eb-477e-896d-50832e2ca9a7
 914    (do not change this comment) */
 915
 916 /* emacsclient.c ends here */